The nation's weather

A cold front will extend from the central Plains to the eastern Great Lakes on Tuesday, while a low pressure system will lose steam over the southeastern corner of the country.

A cold front will stretch across the central Plains, the upper Mississippi Valley and the eastern Great Lakes on Tuesday. As warm, humid air collides with this frontal boundary, strong to severe thunderstorms will develop over the northern tier of the country. Severe thunderstorms will be possible over southern Wisconsin and northern Illinois. These thunderstorms will be capable of producing large hail, dangerous straight line winds and isolated tornadoes. In addition, heavy rain associated with these thunderstorms will bring a slight chance of flash flooding to the upper Mississippi Valley. Scattered showers and thunderstorms will also be possible across the central and southern Plains.

Meanwhile, an area of low pressure will begin to lose steam as it inches over the southeastern corner of the country. Although this system will weaken, widespread rain and thunderstorms will develop over the eastern Gulf Coast, the Southeast, the southern and central Appalachians and the southern Mid-Atlantic. High pressure will keep conditions clear across the Northeast on Tuesday.

Out west, a separate low pressure system will usher showers and stray thunderstorms over the upper Intermountain West, as well as parts of the Great Basin and the Pacific Northwest. High pressure over the eastern Pacific will bring warm, dry weather to the Southwest.

Temperatures in the Lower 48 states Monday have ranged from a morning low of 36 degrees at Bryce Canyon, Utah to a high of 104 degrees at Needles, Calif.